1、Designation: E2975 15E2975 16Standard Test Method forCalibration or Calibration Verification of Concentric CylinderRotational Viscometers1This standard is issued under the fixed designation E2975; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONRotational viscometers have been commonly used for viscosity measurements since the first de
3、cadeof the twentieth century. After more than one hundred years, there have been many ease-of-use,instrumentation, and data analysis improvements in these instruments. The initial constant torqueapparatus gave way to the more popular constant speed apparatus. Spindles became available suppliedwith c
4、alibration constants. Computerization led to factory calibration and automatic viscositycalculation. Even with these improvements, however, apparatus of the very earliest design is stillcommonly used throughout the world. This standard seeks to provide users with the ability to calibrateor verify ca
5、libration of rotational viscosity apparatus in their own laboratory.1. Scope Scope*1.1 This test method describes the calibration (or performance validation)or calibration verification of rotational viscometers inwhich the rotational element is immersed in the test fluid a Newtonian reference materi
6、al under ambient temperature conditions.The method is applicable to rotational-type viscometers where a constant rotational speed results in a measured torque generatedby the test specimen, and to Stormer viscometers where a constant applied torque results in a measured rotational speed. It is notin
7、tended for cone-and-plate or parallel plate viscometers.1.2 Calibration shall be performed with Newtonian reference materials using experimental conditions,conditions such astemperature, viscosity range, and shear rate (rotational speed), as close as practical to those to be used for measurement of
8、testspecimens.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversionsto inch-pound units that are provided for information only and are not considered standard.1.3.1 Common viscosity units of Poise (P) are related to the SI units
9、 by the equivalency 1 cP = 1 mPas.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitati
10、ons prior to use.2. Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and RheologyE1142 Terminology Relating to Thermophysical PropertiesE1970 Practice for Statistical Treatment of Thermoanalytical Data3. Terminology3.1 DefinitionsSpecific technical terms used in
11、this test method are described in Terminologies E473 and E1142 includingNewtonian, non-Newtonian, stress, strain, viscometer, viscometry, and viscosity.1 This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.08 o
12、n Rheology.Current edition approved Sept. 1, 2015Dec. 1, 2016. Published October 2015January 2017. Originally approved in 2014. Last previous edition approved in 20142015 asE2975 14.15. DOI: 10.1520/E2975-15.10.1520/E2975-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or con
13、tactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have be
14、en made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official documen
15、t.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2 Definitions of Terms Specific to This Standard:3.2.1 apparent viscosity (), viscometer, Stormer, nviscosity determi
16、ned by this test method.a rotational viscometer where aconstant torque is applied to a spindle and a resultant rotational speed is measured.3.2.1.1 DiscussionBecause the velocity gradient in this test method may not be the same at all points of the rotational element for non-Newtonianfluids, the res
17、ult determined may not be the true viscosity. Therefore, the viscosity determined by this test method is called the“apparent viscosity.”4. Summary of Test Method4.1 An element A cylindrical spindle is rotated in a Newtonian fluid reference fluid contained in a mating cylindrical containerat a known
18、(or measured) speed. speed at a defined temperature. The viscous drag experienced by the immersed element ismeasured (or known) as a torque. Viscosity may then be determined from these properties (torque and torque. Viscosity isproportional to the torque and inversely proportional to the shear rate
19、(see Eq 1rotational speed) and ). A number of proxies existfor torque and shear rate. For torque, proxies include, but are not limited to, mass (accelerated by gravity operating through amoment arm), and the percent extension of a spring-provided force. For shear rate, proxies include rotational spe
20、ed in a varietyof units including r/min and rad/s, time (for a constant number of revolutions), or number of revolutions (per constant time). Aproportionality constant provides for the dimensions of the rotational element by equations suchspindle and unit conversion (suchas Eq 1 and 2.r/min to rad/s
21、) factors (see Eq 2). 59.55 E S (1) 5 (1)S 5rc2 2 rg2!4 rc2 rg2 L!# (2) 5E (2)where: = viscosity (Pas), = rotational speed (r/min),E = calibration coefficient (dimensionless),E = calibration coefficient, = torque (Nm), andS = rotational element factor (mm-3) supplied by the apparatus vendor,L = leng
22、th of the cylindrically shaped rotational element (mm),rg = radius of the cylindrically shaped rotational element (m), andrc = radius of the cylindrically shaped container (m). = shear rate, S1.NOTE 11 Pa = 1 N/m2; 1 cP = 1 mPas; 1 r/min = 0.1047 rad/s.4.2 The dimensions of the calibration constant
23、depend upon the units in which torque (or its proxy) and rotational speed (or itsproxy) are observed.4.3 Modern apparatus with onboard computers often produce the desired measured viscosity directly. In this case, onlycalibration verification is needed to ensure a properly operating apparatus.4.4 Ca
24、libration or calibration verification of a viscometer and its associated rotational element may be spindle is achieved bycomparing the viscosity indicated by the apparatus with that of the known viscosity of a calibration fluid as their productquotientusing Eq 3, under experimental conditions used i
25、n measuring an unknown fluid:E 5t o (3)C 5t o (3)where:t = the viscosity of the calibration fluid (Pas), ando = the viscosity indicated by the apparatus (Pas).t = the viscosity of the calibration fluid (Pas),o = the viscosity indicated by the apparatus (Pas), andC = calibration verification factor (
26、dimensionless).5. Significance and Use5.1 This test method may be used to calibrate or verify calibration of a rotational viscometer and its associated rotationalelement.with coaxial spindle geometries.E2975 1625.2 The apparent viscosity () of a test specimen may then be obtained using Eq 4: 5E o (4
27、)6. Apparatus6.1 Viscometer, Concentric Cylinder RotationalThe essential instrumentation required providing the minimum rotationalviscometer analytical capabilities for this test method include:6.1.1 Adrive motor, to apply a rotational displacement to the specimen at a rate from 0.50.5 rmin to 60 r/
28、min constant to 60.2% of full scale or alternatively a torque to the specimen at a rate from 100 rmin to 200 rmin constant to 60.2 % of full scale.6.1.2 A coupling shaft, or other means to transmit the rotational displacement from the motor to the specimen.NOTE 2It is convenient to have a mark on th
29、e shaft to indicate the fluid level of the test specimen appropriate for the measurement.6.1.3 A cylindrical rotational element, spindle, bob, or tool, composed of material inert to the material being tested, to fix thespecimen between the drive shaft and a stationary position.NOTE 3Each rotational
30、element spindle typically covers about two decades of viscosity. The rotational element spindle is selected so that themeasured viscosity is between 1510 % and 95 % 100 % of the torque range for that element.spindle.NOTE 4This test method is intended for rotational elements spindles that are immerse
31、d in the test specimen. Newtonian viscosity reference fluidscontained in a mating cylindrical container. It is not intended for cone-and-plate or parallel plate viscometers.6.1.4 Asensor to measure the torque within 61 % of full scale developed by the specimen or alternatively to measure rotationals
32、peed within 61 % of full scale.NOTE 5For Stormer viscometers, this sensor is sometimes a rotational turns-counter and a timer.6.1.5 Atemperature sensor to provide an indication of the specimen temperature of the range of 19C to 26C to within 60.1C.6.1.6 A temperature bath to provide a controlled iso
33、thermal temperature environment for the specimen within the applicabletemperature range of this test method.6.1.7 A temperature controller, capable of maintaining the bath at a temperature constant to 60.1C over the range of 19C to26C.6.1.8 Adata collection device, to provide a means of acquiring, s
34、toring, and displaying measured or calculated signals, or both.The minimum output signals required for rotational viscosity are torque, a signal proportional to torque, a signal proportional toshear rate such as rotational speed, temperature, and time.NOTE 6Manual recording of measured variables is
35、permitted.6.1.9 A stand, to support, level, lower and raise the drive motor, shaft and rotational element.spindle.6.1.10 Aspecimen container, cylindrical in shape suitable for the rotational element spindle (6.1.3), to contain the test specimenduring testing.NOTE 7The specific container may depend u
36、pon the rotational element spindle being used (see vendorsvendors recommendation). In the absenceof other information, a low form low-form Griffin beaker of 600 mL 600-mL capacity shall be used.6.1.11 Auxiliary instrumentation considered necessary or useful in conducting this test method includes:6.
37、1.11.1 Data analysis capability to provide viscosity, stress, or other useful quantities derived from measured signals.6.1.11.2 A level to indicate the vertical plumb of the drive motor, shaft, and rotational element.spindle.NOTE 8Viscometers and their rotational elements spindles are precision equi
38、pment and shall be kept from undue shock and mishandling. Physicaldamage to the instrument may reveal itself as erratic torque or rotational speed indication when the instrument, with or without a rotational element spindlein place, is operated in air. When operating normally, the indicated signal w
39、ill be stable and have a value of zero when operated in air.NOTE 9Care shall be taken in the storage and handling of rotational elements spindles and assemblies. Protect them from dust, corrosive deposits,and mechanical abuse. Avoid touching the calibrated section of the rotational elements spindles
40、 with the hands. Clean the elementspindle and samplecontainer thoroughly after each use.7. Reagents and Materials7.1 One or more viscosity reference fluid (with its accompanying certification) in the range of that anticipated for the testspecimen measurement.NOTE 10Viscosity reference materials are
41、typically available from the viscometer supplier.8. Preparation of Apparatus8.1 Perform any viscometer preparation or calibration procedures described by the manufacturer in the operations manual.8.2 Operate the viscometer in air with a connected rotational element spindle in place. The indicator sh
42、all be stable and indicatea zero value.8.3 Set the temperature bath to 23C and equilibrate for 30 minutes. 30 min. Measure the temperature bath and ensure that itstemperature is 23 6 0.2C.NOTE 11Other temperatures may be used but shall be reported.E2975 1639. Procedure Preparation9.1 Selection of th
43、e Rotational Element: Spindle:9.1.1 From the estimated viscosity of the test specimen, select a rotational element spindle that will produce readings in thedesired range.NOTE 12Where more than one rotational element spindle is available for the range selected, choose an elementa spindle that produce
44、s results nearestthe midpoint of the measurable viscosity range. Viscometer scale reading shall be within the range of 15 to 95 % of full scale.(or torque or rotationalspeed) range.9.2 Preparation of the Viscosity Reference Material:9.2.1 Place the required amount of the reference material measured
45、to the nearest 0.5 mL in the sample container.NOTE 13Pour the reference material slowly down the side of the sample container, taking care to prevent incorporation of air into the material.NOTE 14The amount of viscosity reference material varies with each rotational element spindle and container com
46、bination. See the manufacturersinstruction manual for the correct amount of liquid for each element/containerspindle/container pair.9.2.2 Place the container with its reference material in the temperature bath at 23.0 6 0.2C and equilibrate for 30 minutesmin(see Note 911).9.2.3 Record the viscosity
47、of the calibration material from its certificate at the test temperature T as t.9.3 Assemble the Apparatus:9.3.1 Vertically alignedalign and level the viscometer on its supporting stand.9.3.2 Connect the rotational element spindle selected in 9.1.1 to the coupling link.9.3.3 Align the rotational ele
48、ment spindle (and apparatus) over the sample container.9.4 Rotational Element Spindle Insertion:9.4.1 Slowly lower the rotational element spindle into the reference material container until the fluid covers the element spindleand reaches a level approximately 3 mm above the active area of the elemen
49、t.spindle active area.NOTE 15The shaft may have a mark to indicate the appropriate fluid level for measurement.NOTE 16Take care not to trap any air bubbles under the geometry.spindle.9.4.2 Initiate the rotation of the rotational element spindle at the lowest speed available for 30 minutes.30 min.9.4.3 Measure the temperature of the test specimen (T).NOTE 17If the temperature is not 23.0 6 0.2C, allow the test specimen to equilibrate for an addition 30 min or until the desired temperature rangea
